My LO will be 11 months old this Friday and has been such a great sleeper usually sleeping through the night. These past couple nights though she has been waking up crying at 3 am on the dot, regardless of what time she went to bed. All previous nights, a very quick feed would knock her out again for the rest of the night, but tonight she has only been getting back to sleep for a couple of minutes before crying very tiredly. Is this something other babies are going through or could it be an indication of something else that we should get checked out with the pediatrician?